SANDPIPER MSB25 - Manual (Page 8)

msb1dl5sm-rev0813 Models MSB1 & MSB25 Page 6
AIR INLET & PRIMING
For start-up, open an air valve approximately 1/2" to 3/4" turn. After the unit
primes, an air valve can be opened to increase flow as desired. If opening the valve
increases cycling rate, but does not increase flow rate, cavitation has occurred, and the
valve should be closed slightly.
For the most efficient use of compressed air and the longest diaphragm life, throttle
the air inlet to the lowest cycling rate that does not reduce flow.
AIR EXHAUST
If a diaphragm fails, the pumped liquid or fumes can enter the air end of the pump,
and be exhausted into the atmosphere. When pumping hazardous or toxic materials,
pipe the exhaust to an appropriate area for safe disposition.
This pump can be submerged if materials of construction are compatible with the
liquid. The air exhaust must be piped above the liquid level. Piping used for the air
exhaust must not be smaller than 1" (2.54 cm). Reducing the pipe size will restrict air
flow and reduce pump performance. When the product source is at a higher level than
the pump (flooded suction), pipe the exhaust higher than the product source to prevent
siphoning spills.
Freezing or icing-up of the air exhaust can occur under certain temperature and
humidity conditions. Use of an air dryer should eliminate most icing problems.
BETWEEN USES
When used for materials that tend to settle out or transform to solid form, the pump
should be completely flushed after each use, to prevent damage. Product remaining
in the pump between uses could dry out or settle out. This could cause problems with
valves and diaphragms at re-start. In freezing temperatures, the pump must be drained
between uses in all cases.
CHECK VALVE SERVICING
Need for inspection or service is usually indicated by poor priming, unstable
cycling, reduced performance or the pump’s cycling but not pumping.
Remove the six flange bolts securing the inlet and outlet flanges to the manifold. In-
spect the surfaces of both check valve and seat for wear or damage that could prevent
proper sealing. If pump is to prime properly, valves must seat air tight.
DIAPHRAGM SERVICING
Remove the four bolts securing the manifold flange to the chamber. Remove the eight
nuts securing the outer diaphragm chamber flange and remove the chamber. Loosen
the capscrew securing the diaphragm and plate to the rod by leaving the diaphragm
engaged with the capscrews around the outer flange, preventing rotation of the rod. DO
NOT USE A WRENCH ON THE DIAPHRAGM ROD. FLAWS ON THE SURFACE MAY
DAMAGE BEARINGS AND SEAL.
During reassembly make certain that the rubber bumper is on the rod on each
side. Install the diaphragm with the natural bulge outward as indicated on the
diaphragm. Install the heavier plate on the outside of the diaphragm and make
certain that the large radius side of both plates are toward the diaphragm. Place the
sealing washer between the inner diaphragm plate and the end of the rod. Tighten the
capscrew to approximately 25 ft. lbs. (33.9 Newton meters). Torque while allowing dia-
phragm to turn freely with plates. Except for EPDM Rubber, use a lightweight oil between
plates and diaphragm when doing this procedure. Use a wrench on the capscrew of
the opposite side to keep the rod from rotating. If the opposite chamber is assembled,
the rod need not be held.
When reassembling the outer chambers and the manifold, the bolts securing the
manifold flange to the chamber should be snugged prior to tightening the chamber
bolts, to insure that the chamber port flange is square with the manifold flange. Finish
tightening the manifold flange bolts after chamber bolting is secured.
AIR VALVE LUBRICATION
The SANDPlPER pump’s pilot valve and main air valve assemblies are
designed to operate WITHOUT lubrication. This is the preferred mode of
operation. There may be instances of personal preference, or poor quality air
supplies when lubrication of the compressed air supply is required. The pump air
system will operate with properly lubricated compressed air supplies. Proper lubrication of the
compressed air supply would entail the use of an air line lubricator (available from Warren